code: def test_fetch_hash(self):
      with self._exp() as exp:
          var = Artifact(exp, self._random_path())
          var._enqueue_operation(
              AssignArtifact(
                  var._path,
                  ArtifactVal(
                      "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
                  ).hash,
              ),
              wait=False,
          )
          self.assertEqual(
              "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
              var.fetch_hash(),
          )
  
file_path: neptune-client/tests/unit/neptune/new/attributes/atoms/test_artifact_hash.py
imports: from mock import MagicMock
  from neptune.attributes.atoms.artifact import Artifact
  from neptune.internal.operation import AssignArtifact
  from neptune.types.atoms.artifact import Artifact
  from tests.unit.neptune.new.attributes.test_attribute_base import TestAttributeBase
label_desc: Use image node_id 3 for calling the TestArtifactHash obj's underlying member method code with example usage: obj.test_fetch_hash() without return types